Air-pump.



J. DESMOND.

AIR PUMP.

APPLICATION FILED DEC. 27, 1909.

Patented Feb. 21, 1911.

v a 72 Udzi/ILU/LCZ. j/ M L UNITED STATES PATENT OFFICE.

JOHN DESMONID, OF CHICAGO, ILLINOIS, AssIenoR TO NICKEL manurao'rnnms 7 COMPANY, OF MORRIS, ILLINOIS, A CORPORATION OF ILLINOIS.

Patented Feb. 21, 191] I AIR-PUMP.

985,013, Specification of Letters Patent.

I Application filed December 27 1909. Serial No. 535,053.

To all whom it may concern:

Be .it known that I, JO N DESMOND, a"

citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Air-Pumps, of which the following is a specification.

This invention relates more particularly to air pumps adapted to be' attached to antomobiles, for the purpose of inflating the tires; and has for its object, to construct a pump, which, when it has been actuated sufliciently to accumulate a certain pressure in a storage tank or in a tire, will be automatically prevented from effecting further compression. And the invention further consists in the features of construction and combination of parts hereinafter described and claimed. I A

The drawing shows a cross section of a pump and cut-ofl" mechanism therefor in operative position.

The pump consists of an outer shell or casing 2, comprising a base 3 and an upwardly extending, cylindrical portion 4, which is composed of a lower chamber 5 and an upper chamber 6. Located in the lower chamber 5 is a main driving shaft 7, driven by the motor of an automobile or by other suitable means. Attached to the shaft 7 is a crank arm 8, to the end of which is connected a piston rod 9, screw-threaded at its upper end into a ball 10 lying within a re cess 11 formed in a piston head '12, the ball and recess forming an ordinary ball joint, which acts to perform the functions in the manner usual to such devices.

.The piston 12 consists of an outer shell 13, provided with a plurality of packing rin s 14 and an inner section 15, in which is t ormed the recess 11. The inner section is held in place by a nut 16, and upon the upper end of the casing 2 is a screw-threaded plug 17, provided with a passageway 18, which connects with a-passageway 19 in a plug 20, and to which is attached a tube 21. Positioned in the passageway 18 is a ball valve 22, reventing the return ofair into the cylin er after it has been forced out which openings and chamber form a commu- "nication between the piston chamber and the outside air, and this communication is made and broken by the movements of a valve 27 consisting of a valve member 28 resting against the seat- 24 and a valve stem 29 which is mounted within a hub 30 formed in the plug 25, and is provided, on its upper end, with a thumb nut 31, between which and the hub 29 is interposed a coil-spring 32.

Positioned above the thumb nut 31 is an arm 33, pivoted to an upwardly extending lug 34 formed with a diaphragm casing 35,

in which rests a diaphragm member 36 held in place between a ring 37 andthe inwardly ex'tendlng flange. of the diaphragm casing. The ring is formed suitable passageway 39. Resting upon the 41, the end of which rests against one end of the arm 33. The stem 38 is clamped between plates 42, which surroundthe cylinder and are held together by bolts, or other wise. The passage 39 communicates with a passage 43 formed in a nipple 44, and the nipple and stem 38 are joined togetherby a coupling nut 45. The threaded into one end of a T-coupling 46, to the opposite end of which is connected a hose 47 adapted to beattached to a storage tank or tire. And the T-coupling has also connected thereto the tube 21 leading from the piston chamber.

The operation is as' follows: When the piston 12 is drawn downwardly,- it creates a suction, which unseats the valve member 28 and draws air into the piston. chamber. As the piston is moved upwardly, the air is forced through the opening 18 into the tube- 21 and thence to the chamber, where it is being accumulated. This'action is continued until a predetermined pressure, as eighty pounds, has been produced in the chamber, and when such pressure is reached, the diaphragm 36 will be actuated, raising the pin 41, which will swing the arm 33, causing it to depress the valve 27, unseating the valve member and establishing communication between the piston chamber and the outside air. And this communication will be established until the pressure in the chamber has upon a, disk 37 from whlch depends a stem 38,- provided with a nipple 44 is ,screwbeen reduced below that desired. The establishing of communication between the outside air and the piston chamber, of course,

' therein.

prevents any further air from being forced into the tube 21. This method, which prevents further compression of the air after-a certain pressure'has been created within the chamber where it is being accumulated, is of great importance in the inflating of automo-' bile tires, where an excess of pressure is liable to result in a blow-out in the tire, and the obtaining of an excess pressure is very likely to occur, since there are-no means'of determining by anage, or other mechanical means, just what pressure has been obtained While the pump has been described as attached to an automobile and actuated by the motor thereof, it is, of course, evident-that it can'be used under other conditions without departing from the spirit of theinvention. As shown, the upper face of the piston is recessed to form a cup 48, into which the oil, which is scraped from the wall of thepiston chamber "by thepiston during its'movements, will collect;

piston. ,By this means the. oil will be re moved from the compression chamber, so that it will not be forced into thetube 21.. with the air,.and at the same time the ball and socket connection will'receive constant to provide valve seats, a ball valve arran edlubrication. The oil forms a seal so that no air' will filter through the passa es in the piston head and thus reduce the e ciency of the pump, I claim: r :1. In a pump, a' cylinder having; a removable head provided with inde endentinlet and outlet passages therein, both of said passages being contracted at their inner ends within one passage and resting in its va ve '45 seat, a perforated plug detachably threaded in the outer end of the inlet passage and havin a central guide hub, a valve stem slidab y mounted in said hub and having a valve at its inner end normally resting in the valve seat in said inlet passage an adjusting nut threaded on the outer en of said rod, a 'coiled expansion s ring surrounding the rod and having its en 5 engaging the inner face of the nut and the outer face of the plug, respectively, a piston working in said cylinder and a delivery pipe leading from and having detachable connection with the outlet passage of said, cylinder.

2. Ina pump, a cylinder having a removable head provided withindeendent inlet and outlet passages therein, 0th of said passages bein contracted at their inner ends to provide va ve seats, a ball valve arran ed within one passage and resting in its va ve seat, a perforated plug det-achably threaded in the outer end of the inlet passage and havin a central guide hub, a valve stem slidab ymounted in said hub and having a valvelat its inner end normally resting in the valve seat in said inlet passage, an ad usting nut threaded on the outer end of said rod, a coiled expansion spring surrounding the rod and having its ends engaging the inner face of the nut and the outer face of the plug, respectively, a piston working in said cylinoder, a deliverypipe leading from and having detachable connection. with the outlet passe of said cylinder, and means independent of and detachably connected with the cylinder and having communication with the free end of said delivery pipe and :acting on the outer end of the va ve stem to automatically open its valve when a predotermined amount of fluid has been ejected from the cylinder for exhaust-ing the re- [maining pressure in the latter.

' .JOHN DESMOND.

Witnesses:

WM. P. Bonn,

EPHRAIM BANKING. 

